This specification relates to identifying and using relationships between search entities.
Internet search engines provide information about Internet accessible documents (e.g., Web pages, images, text documents, multimedia content) that are responsive to a user's search query and present information about the resources in a manner that is useful to the user. Internet search engines return a set of search results (e.g., as a ranked list of results) in response to a user submitted query. A search result includes, for example, a Uniform Resource Locator (URL) and a snippet of information from a corresponding document.
Each time a user submits a search query and receives results, several search entities are typically involved, including, for example, the query the user submits, documents that are responsive to the query, the search session during which the user submits the query, the time at which the query is submitted, and advertisements presented in response to the query.